1. Knowing that you don’t know, and consistency in false memory
James A. Hampton and Priya Gorasia Department of Psychology, City University London
Abstract
Student’s memories for details of a TV show were tested after 3 days and again after 5 days. A group who judged statements Definitely True, Uncertain, or Definitely False were more consistent across tests than a group who judged the statements simply True or False, implying the involvement of metamemory. Improved accuracy was however limited to True statements.
The Rumsfeld Effect
General Knowledge
Using three options led to greater consistency across time
There are statements which are “Known Unknowns”
These attract stable Uncertain judgments
Categorization, autobiographical memories, likes and aspirations
Using three options is no more consistent than using two
There are only “Unknown Unknowns”
Results: Consistency of memory A B 3 2 1 1 4
3-option group more consistent than the 2-option group for both True and False statements.
“Uncertain” responses for the 3-option group were as consistent as Definitely True responses (around 80%) – the “known unknowns”
False statements (red) judged as “Definitely” True remained firmly in memory with near 80% consistency
But True statements (blue) judged as Definitely False were unstable on retest, compared with False statements correctly judged Definitely False
Calculating consistency
For the 2 response case, consistency is the likelihood of giving the same response on each occasion
For the 3 response case, consistency is the mean of
the consistency of a Definite Yes
the consistency of a Definite No
Second response
First response
Definitely YES
MAYBE
Definitely NO
The yellow cells are counted as Consistent for a Definite Yes Response.
A Definite No uses the equivalent cells based on the lower right corner
Metamemory and the Rumsfeld Effect
Hampton et al. (2011): a new method for testing the reliability of judgments of truth/falsity of uncertain or vague statements
Sociology is a Science – True or False?
GROUP A: judged statements with a binary choice:
TRUE or FALSE
GROUP B: judged statements with three options:
DEFINITELY TRUE UNCERTAIN DEFINITELY FALSE
Group B were able to choose only the “easy” statements for judging true or false, and any statements that were doubtful could be left as uncertain.
Group A had to guess if they were not confident of the answer.
How reliable would people be when tested in the same way a week later?
Does the option of responding only to the obviously clear statements lead to a greater consistency across time?
Or does the metacognitive difficulty of deciding when a statement’s truth is uncertain or not lead to no improvement in consistency?
A number of different domains were studied:
General knowledge: the Uruguayan flag has red in it
Categorization in semantic domains: a tomato is a fruit
Autobiographical memories: I once was on a bus when it broke down
Likes and dislikes: I like peanut butter
Aspirations: I would like to meet the Queen
Accuracy
Testing certainty for memories
Will judgments of event memories show greater consistency in the 3 response condition that includes an Uncertain response?
Will the 3 response condition give more accurate responses for those statements judged Definitely True or False?
How stable are highly confident but false memories?
Participants: 59 students aged at a London college
Procedure: Watched a clip from a TV show. Memory tested after 3 days and retested after 5 days, using a list of 40 statements.
Monk washed his toothbrush with soap
Design:
A) Number of Response Options – between subjects
Two response options: True/False
Three response options: Definitely True, Uncertain, Definitely False
B) Statement Truth
20 true and 20 false statements
Test/Retest
Each statement was tested after 3 days, and again after 5 days
the 3-option group were more accurate than the 2-option group for True statements, t(57) = 7.4, p < .001,
but not for False statements t(57) = 1.2, NS
Conclusions
Allowing an “Uncertain” response in this task leads to improved consistency and improved accuracy for True statements judged Definitely True
Even when definitely certain of a response, stability was only 80% after a 2 day delay
False Positives were very stable, but False Negatives were not
True statements benefited in accuracy from the 3-options, but False statements did not.
Reference: Hampton, J.A., Aina, B., Andersson, J.M., Mirza, H., & Parmar, S. (2012). The Rumsfeld Effect: the Unknown Unknown. Journal of Experimental Psychology: Learning Memory & Cognition, 38,
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